January 23, 2007

From time to time a book or idea catches on in the media and you can't read a periodical without running across it. For me this has been the case with A. Roger Ekirch and his book At Day's Close: Night in Times Past.

The main idea that seems to have caught the imagination of more than one is that in times past we have slept many more hours than we do now. Without the intrusion of electric light, slumber was reached hours earlier, and it was even punctuated by a period of sleeplessness in the middle of the night. Waking up in the middle of the night is thus seen as natural and should serve as word of comfort to insomniacs everywhere. In all humans likely achieved nearly nine hours of sleep each night.

Humans are the only monophasic sleeper, that is, among mammals they are the only species with consolidated sleep. Spaniards, college students, babies, and retirees don't follow this rule. Just as omnivory approximates our natural state, so does frequent napping. The problem lies in the way we have structured the working day, or worse yet, how we have structured the medical resident's eighty-hour week.